Throughout this application, including in the claims, the term “knife” is used in a broad sense to denote a sharp object (e.g., a punch or sharp-tipped object) capable of scarifying the surface of an article of fruit.
Throughout this application, including in the claims, the expression that two or more actions occur “contemporaneously” denotes that the actions occur during overlapping time intervals, or simultaneously, or during time intervals that nearly overlap. For example, advancing two knives “contemporaneously” into an article of fruit such that neither of the knives advances so far into the fruit that its tip protrudes out from the fruit assumes that one knife pierces the fruit at a time “T1” and ceases to advance at a later time “T2,” and that the other knife pierces the fruit at a time “T3” and ceases to advance at a time “T4,” where T4 is later than T3. Herein the expression “advancing two knives contemporaneously” into an article of fruit (such that neither of the knives advances so far into the fruit that its tip protrudes out from the fruit) can denote advancing the knives simultaneously into the fruit (so that T1 is at least substantially equal to T3, and T2 is at least substantially equal to T4), or advancing the knives such that at least a portion of the interval from T1 to T2 occurs simultaneously with at least a portion of the interval from T3 to T4 (which could occur even if one of the knives begins to retract out from the fruit before the other knife ceases to advance into the fruit), or advancing the knives such that the interval from T1 to T2 occurs before (does not overlap) the interval from T3 to T4 but the difference between T3 and T4 is very small relative to the smaller of (T4−T3) and (T2−T1).
Throughout this application, including in the claims, the term “horizontal” denotes an arbitrary direction (which can be, but is not necessarily, a direction perpendicular to the earth's gravitational field) and the term “vertical” denotes a direction perpendicular to a specific “horizontal” direction. For example, preferred embodiments of the inventive apparatus have elements which define cam tracks and which rotate as a unit with a “horizontally” oriented drive shaft. As the elements rotate, the cam tracks cause knives to advance and retract horizontally. The drive shaft's longitudinal axis is preferably oriented perpendicularly to the earth's gravitational field (since this orientation allows gravity to pull fruit fragments and/or juice perpendicularly away from the knives of the inventive apparatus during operation), but it need not be and is not in some implementations of the invention.
It is often commercially useful to scarify (make at least one shallow cut in, or otherwise pierce) the surface (outer membrane or skin) of an article of fruit. For example, it is commercially useful to scarify the surfaces of frozen cranberries so that sugar can be added efficiently to the scarified cranberries (typically by immersing the scarified cranberries in sugar solution). Unless the outer membrane of a cranberry is scarified before the cranberry is immersed in sugar solution, sugar cannot efficiently be infused into the cranberry by immersion of the fruit in sugar solution.
U.S. Patent Application Publication No. 2004/0142072, published Jul. 22, 2004, describes a conventional method and apparatus for scarifying frozen cranberries and subsequently infusing sugar into the scarified cranberries. The apparatus employs a tapered punch to pierce each frozen cranberry, either completely (with the punch entering a first side of the fruit and advancing all the way through the fruit until its tip protrudes from the fruit's opposite side, and then retracting from the fruit through the first side) or partially (with the punch entering a first side of the fruit and advancing only partway into the fruit so that its tip does not protrude out from the fruit's opposite side, and then retracting from the fruit through the first side of the fruit). The reference teaches that the punch's outer diameter, D, at its untapered end, is typically in the range from about 2 mm to about 4 mm, and that the punch is typically advanced all the way through the fruit and then retracted so as to leave in the fruit an entrance hole of approximate diameter D and an exit hole of diameter less than D.
The inventors have recognized that employing an apparatus (e.g., as described in U.S. Patent Application Publication No. 2004/0142072) to advance a knife (e.g., a punch) completely through a frozen cranberry (or other frozen fruit) can cause the fruit to break into large pieces (or even to explode), and typically, undesirably produces scarified fruit whose size is substantially smaller than that of the original (unscarified) fruit and whose shape is undesirably altered (e.g., made irregular) by the scarification process. The inventors have also recognized that it is inefficient and otherwise undesirable to scarify an article of fruit (e.g., a frozen cranberry) by advancing a single knife (e.g., a punch as described in U.S. Patent App. Publication No. 2004/0142072) through a first side of the fruit, partially into the fruit so that the knife's tip does not protrude out from the fruit's opposite side, and then retracting the knife in the opposite direction out from the fruit through the first side. Such an operation of using a single knife to pierce partway through a fruit (by advancing the knife into a first side of the fruit) scarifies only the first side of the fruit, undesirably leaving the rest of the fruit's skin intact.
The inventors have recognized that it would be desirable to employ multiple knives to scarify an article of fruit by advancing them contemporaneously (e.g., simultaneously) into the fruit through at least two locations on the surface of the fruit (so that the none of the knives advances so far that its tip protrudes out from the fruit), and then retracting the knives out from the fruit. Such an operation of using multiple knives to pierce partway through a fruit efficiently scarifies multiple locations of the fruit's surface.
One type of multi-knife apparatus capable of scarifying fruit is an apparatus designed for pitting and slicing olives, of any of the types described in U.S. Pat. No. 4,925,691, issued May 15, 1990, and in U.S. Pat. No. 4,876,954, issued Oct. 31, 1989, and in U.S. Pat. No. 6,969,535, issued Nov. 29, 2005, all assigned to the assignee of the present invention. In typical implementations of such apparatus, cam-driven pitting and coring knives advance and retract horizontally to pit olives as the knives (and olives) are carried along a generally circular path around a horizontal shaft. Each olive rests in a cup while the olive has its pit removed by an advancing pitting knife, as both the olive and cup translate along a first segment of the circular path around the horizontal shaft. The pitted olive is then sliced by fixed or rotating slicing knives (or water jets) while the pitted olive (still in the cup) translates along a second segment of the circular path around the horizontal shaft. The inventors have recognized that since such an apparatus undesirably advances a knife completely through an article of fruit (the advancing knife's tip exits the fruit so as to eject the pit from within the fruit), use of such an apparatus to pierce a frozen fruit (e.g., a frozen cranberry or blueberry) would be likely to break the frozen fruit (undesirably) into large pieces (or even to cause the fruit to explode), and would likely (undesirably) produce scarified frozen fruit whose size is substantially smaller than that of the original (unscarified) fruit and whose shape is undesirably altered (e.g., made irregular) by the action of the knives on the fruit.
Another type of multi-knife apparatus capable of scarifying fruit is an apparatus designed for pitting olives, of any of the types described in U.S. Pat. No. 4,871,568, issued Oct. 3, 1989, and assigned to the assignee of the present invention. In operation of such apparatus, opposed cam-driven pitting knives (or opposed cam-driven coring knives) advance and retract horizontally to pit olives as the knives (and olives) are carried along a generally circular path around a horizontal shaft. Each olive rests in a cup while the olive has its pit removed by an advancing pitting (or coring) knife, as both the olive and cup translate along a first segment of the circular path around the horizontal shaft. The inventors have recognized that since such an apparatus undesirably advances a knife completely through an article of fruit (the advancing knife's tip exits the fruit so as to eject the pit from within the fruit), use of such an apparatus to pierce a frozen fruit (e.g., a frozen cranberry) would be likely to break the frozen fruit (undesirably) into large pieces (or even to cause the fruit to explode), and would likely (undesirably) produce scarified frozen fruit whose size is substantially smaller than that of the original (unscarified) fruit and whose shape is undesirably altered (e.g., made irregular) by the action of the knives on the fruit.